N 2-(7-Bromo-9-butyl-9H-carbazol-2-yl)-9,9-diethyl-N 2,N 7,N 7-triphenyl-9H-fluorene-2,7-diamine

In the title molecule, C51H46BrN3, the central fluorene residue is planar (r.m.s. deviation = 0.0203 Å), as is the carbazole system (r.m.s. deviation = 0.0154 Å), and these groups are almost orthogonal [dihedral angle = 79.72 (3)°]. The three-dimensional architecture is consolidated by C—H⋯π interactions. The butyl substituent is disordered with two sites resolved for the terminal propyl atoms; the major component had a site-occupancy factor of 0.686 (3).

In the title molecule, C 51 H 46 BrN 3 , the central fluorene residue is planar (r.m.s. deviation = 0.0203 Å ), as is the carbazole system (r.m.s. deviation = 0.0154 Å ), and these groups are almost orthogonal [dihedral angle = 79.72 (3) ]. The threedimensional architecture is consolidated by C-HÁ Á Á interactions. The butyl substituent is disordered with two sites resolved for the terminal propyl atoms; the major component had a site-occupancy factor of 0.686 (3).

Related literature
For the use of carbazole and fluorene derivatives as holetransporting and emitting materials in organic light-emitting diodes and as sensitizers in dye-sensitized solar cells, see: Thomas et al. (2001Thomas et al. ( , 2004; Baheti et al. (2009Baheti et al. ( , 2011.  Table 1 Hydrogen-bond geometry (Å , ).
KRJT is thankful to Department of Science and Technology, New Delhi, India, for financial support (ref. No. DST/ TSG/ME/2010/27). We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/ 12).
Similarly, the 13 non-hydrogen atoms of the carbazole system forms a plane (r.m.s. deviation = 0.0154 Å). The dihedral angle between the fluorene and carbazole fused ring systems is 79.72 (3)°, indicating an almost orthogonal relationship.
The fluorene system forms dihedral angles of 88.22 (6) and 58.51 (7)° with the C1-C6 and C7-C12 N1-amine-phenyl rings, respectively; the dihedral angle between these phenyl rings is 64.45 (8) °. At the N2-amine side of the molecule, the dihedral angles formed between the fluorene and carbazole fused ring systems with the N2-bound phenyl ring are 62.96 (6) and 71.53 (6)°, respectively. With respect to the five-membered ring in the fluorene residue, the ethyl substituents are virtually perpendicular as seen in the values of the C17-C25-C26-C27 and C17-C25-C28-C29 torsion angles of 54.4 (3) and -60.6 (3)°, respectively. Finally, the major component of the disordered n-butyl chain adopts an extended trans conformation with the C48-C49-C50-C51 torsion angle being 173.2 (3)°; the equivalent value for the minor component Molecules are consolidated in the three-dimensional architecture by C-H···π interactions, Fig. 2 and Table 1.

Refinement
Carbon-bound H-atoms were placed in calculated positions [C-H 0.95 to 0.99 Å, U iso (H) 1.2 to 1.5U eq (C)] and were included in the refinement in the riding model approximation. The terminal propyl group of the butyl substituent was found to be disordered. Two sites were resolved and from fractional refinement (common anisotropic displacement parameters for pairs of atoms, and with 1,2-and 1,3-C-C distance constraints = 1.50±0.01 and 2.35±0.01 Å, respectively). The major component had a site occupancy factor = 0.686 (3).

Figure 1
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level. Only the major component of the disordered n-butyl group is shown for reasons of clarity.    T min = 0.836, T max = 1.000 17423 measured reflections 8220 independent reflections 7219 reflections with I > 2σ(I) Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.